Asthma is the most common chronic condition of childhood in Australia. Most families manage it with inhalers and GP visits — which makes sense, because that is what the medical system is set up to offer.
What the medical system rarely asks about is the home.
Yet the research is clear: the indoor environment is the most important driver of how well a child's asthma is controlled. Not the medication. The home they sleep in every night.
What's Actually in Your Home
Children spend most of their time indoors. Research shows that indoor air pollutants have a greater effect on childhood asthma than outdoor pollution — yet outdoor air quality gets the headlines.
Over 92% of homes contain enough of at least one allergen to trigger symptoms in a sensitised child. Nearly half have three or more allergens at elevated levels.
The main culprits:
- Dust mite allergens in mattresses, carpets and bedding
- Mould spores from damp walls, subfloors and ceiling cavities
- Pet dander
- Combustion products from gas cooking and heating
- Cockroach and rodent allergens in older or poorly maintained homes
Most families are living with these exposures without knowing it.
Mould and Damp: The Factor Most Families Miss
Of all the home environment factors linked to childhood asthma, mould and dampness have the most consistent and compelling evidence behind them.
- A systematic review of 135 studies found a clear link between visible mould and developing asthma before age nine
- Children exposed to damp in early life were more than seven times more likely to develop asthma by age three
- Children in homes with mould or damp are 50% more likely to have asthma or wheezing than those in dry homes
For Australian families specifically, research in the Medical Journal of Australia found:
- 26% of Australian homes have dampness problems
- Damp housing accounts for around 8% of the total childhood asthma burden nationally
- Gas stoves account for a further 12% where ranges are poorly ventilated
If you have a gas cooktop and any signs of moisture in your home, these are not background factors. They are meaningful contributors to your child's lung health.
A 2025 multicentre study of 424 asthmatic children found that those in homes with moisture and mould were significantly more likely to have poorly controlled asthma and more unscheduled medical visits. The home environment was directly predicting how often children ended up in emergency care.
The Bedroom Is the Most Important Room
Dust mites are one of the most potent asthma allergens for children. They thrive in warm, humid conditions and concentrate in exactly the places your child spends the most time — mattresses, pillows, carpets and upholstered furniture.
In sensitised children, dust mite exposure is associated with:
- Increased bronchial hyperresponsiveness
- Impaired lung function
- Higher levels of airway inflammation
The good news is that the bedroom is the most controllable space in the home. The catch is that one change on its own rarely moves the needle. The research is consistent on this: single interventions targeting one allergen produce minimal clinical benefit. What works is reducing the overall load across multiple triggers at the same time.
The Evidence on Fixing the Home
A landmark trial published in the New England Journal of Medicine enrolled 937 children with atopic asthma across seven US cities. A whole-home intervention targeting multiple allergens simultaneously produced sustained improvements in asthma outcomes over two years. No previous single-allergen study had achieved anything close.
A Cochrane review of 12 studies found that repairing mould-damaged homes reduced asthma symptoms and medication use. In one study, emergency department visits and hospitalisations among children dropped from 33% to just 4% after home remediation.
Not new medication. A better home environment.
What Parents Can Do Right Now
You do not need a professional assessment to start. Here is where to begin:
- Find and fix moisture first. Check for water stains, condensation on windows, musty smells and any history of leaks. Moisture drives mould, and mould drives asthma. Nothing else matters as much as addressing the source.
- Prioritise the bedroom. Encase your child's mattress and pillow in allergen-impermeable covers. Wash all bedding at 60°C weekly. Remove soft toys from the bed or wash them regularly.
- Lower bedroom humidity. Dust mites cannot survive in low humidity. Keep it below 50% using ventilation, a dehumidifier or air conditioning where possible.
- Vacuum with a sealed HEPA system. Standard vacuums push fine particles back into the air. A sealed HEPA vacuum removes them. Focus on the mattress, carpets and upholstered furniture.
- Ventilate when using the stove. Gas cooktops produce nitrogen dioxide — a respiratory irritant directly linked to childhood asthma. Use rangehood extraction on high, open windows, and consider switching to induction if asthma is poorly controlled.
- Simplify soft furnishings in the bedroom. Carpets, heavy curtains and stuffed toys harbour allergens. Hard floors, blinds and washable rugs are meaningfully better for an asthmatic child's sleeping space.
- Keep pets out of the bedroom. Pet dander is a significant sensitiser. A pet-free sleeping zone is one of the highest-impact changes a family can make.
- Switch to unscented cleaning products. Fragranced products and air fresheners are respiratory irritants that can drive airway inflammation in sensitive children.
When to Go Further
If your child's asthma remains poorly controlled despite these steps, or you suspect mould inside walls, a systematic home assessment is the logical next step. A whole-home evaluation — covering moisture, mould, allergen sources, ventilation and gas appliances — can identify what a checklist at a GP appointment cannot.
A Dwellness home assessment works alongside integrative health practitioners to give families a clear, prioritised picture of what the home is contributing to their child's health.
Book a free consultation to discuss a home assessment for your child.